Oregon getting to the National Championship game is an anomaly. When you look through the national recruiting rankings...Oregon isn't built for a national title run...in fact, only USC, east of Texas is built for it (and they proved that). Even with Chip Kelly as the head coach, it didn't do a whole bunch for their recruiting. Kelly returning, wouldn't change much, IMO. These rankings are based on ESPN, FYI.
If I were Chip Kelly and really did want to return...there is only one place I'd look, The University of Texas.
Oregon's recruiting rankings:
2015: 15th
2014: 27th
2013: 26th
2012: 18th
2011: 14th
2010: 22nd
2009: out of top -25
2008: out of top-25
When compared to all the winners over the last 15 years, Oregon is a gigantic outlier to have even made the national title game. Long story short...with or without Nike, the uniforms, etc...Oregon still is destined to be a team that finished 8-15. Oregon is what they are...fun to watch, but not a National Powerhouse program.
Also, there should be no surprise that Oregon is struggling this year a little (especially on D)...their mainstay players are from recruiting classes ranked outside of the top-25.